1. Field of the Invention
The present invention generally relates to the field of data processing systems, and more particularly is directed to a data processing system with a first program of computer instructions and a second program of computer instructions for prohibiting the first program from using the second program. Specifically, the invention is directed to an IC card with a CPU which operates in accordance with the first program written by a user and a second program written by the card maker for prohibiting program instructions in the first program from directly using program instructions in the second program.
2. Description of the Related Art
An IC card includes a microprocessor within the card as shown in U.S. Pat. No. 4,211,919. An advantage of an IC card is that it may be used to maintain confidential information. For example, no one can access information stored in the IC card without a personal identification number.
A card issuer, such as a bank, would not want the card manufacturer to know the particular application programs used by the bank. Thus, the card maker provides merely a basic operations program resident in the IC card when shipped. The card issuer then provides the application program for his service. Thus, the card manufacturer can supply the same IC card without application programs to a variety of card issuers. It is important for the card maker to maintain the basic operating program and information relating thereto confidential from the card issuer. If the card issuer could determine the structure and nature of the basic operating program, the card issuer could eliminate a need for the card maker.